This specification relates to resolving geographic location criteria for performing actions in response to user requests.
Systems exist that perform certain actions in response to a user request only if the location of the user submitting the request satisfies one or more location criteria for performing the actions. However, the locations of users as determined by the systems may be associated with varying degrees of uncertainty. For example, some systems determine a user location as a location, e.g., a latitude and longitude pair, and an associated confidence radius. The confidence radius defines a region of confidence centered at the location. The region of confidence includes all of the possible locations for the user as determined by the system and is a representation of the uncertainty of the system in determining a precise location for the user.
Because of the uncertainty associated with user locations, some systems maintain data that represents the location criteria for a request as a target region for the request and a confidence threshold for the target region. The target region is a geographic region in which a user should be located in order for the location criteria for the alert to be satisfied. The confidence threshold defines how confident the system must be that the user is located in the target region for the location criteria to be satisfied. When a user request that includes location data that identifies a user location and a confidence radius for the location is received, in order to determine whether the location criteria for an action are satisfied, such systems determine an area of intersection between the region of confidence for the user location and the target region for the action. If the ratio of the area of intersection to the area of the region of confidence exceeds the confidence threshold, the systems determine that the location criteria are satisfied. If the ratio does not exceed the confidence threshold, the systems determine that the location criteria are not satisfied. Thus, these existing systems account for uncertainty in user locations, but must determine the area of intersection for every request that is received.